Power management in transceivers

ABSTRACT

Various embodiments are directed to apparatuses and methods to generate a first signal representing modulation data and a second signal representing an amplitude of the modulation data, the first signal and the second signal to depend on an output signal and vary a power supply voltage to a gain stage in proportion to the amplitude of the modulation data.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of, claims the benefit of andpriority to previously filed U.S. patent application Ser. No. 16/251,476filed Jan. 18, 2019, entitled “Power Management in Transceivers”, whichis a continuation of, claims the benefit of and priority to previouslyfiled U.S. patent application Ser. No. 15/659,857 filed Jul. 26, 2017issued as U.S. Pat. No. 10,224,883, which is a continuation of, claimsthe benefit of and priority to previously filed U.S. patent applicationSer. No. 14/643,164 filed Mar. 10, 2015 issued as U.S. Pat. No.9,729,112, which is a continuation of, claims the benefit of andpriority to previously filed U.S. patent application Ser. No. 14/255,444filed Apr. 17, 2014 issued as U.S. Pat. No. 9,000,843, which is acontinuation of, claims the benefit of and priority to previously filedU.S. patent application Ser. No. 13/330,412 filed Dec. 19, 2011 issuedas U.S. Pat. No. 8,742,843, all of which are incorporated herein byreference in their entireties.

BACKGROUND

Power amplifier stages may process varying amplitude signals and may beimplemented such that an output stage can support a maximum outputvoltage swing. This may define a maximum supply voltage (Vcc) to preventsaturation of a transconductance stage. The linearity of the outputstage may typically be set to deliver the required linearity at themaximum output. As a consequence the power consumed by the output stagemay be disadvantageously constant at a maximum value set by the maximumoutput amplitude. This may be undesirable since power is wasted when thetransceiver is transmitting at a reduced output amplitude. Accordingly,there may be a need for improved techniques to solve these and otherproblems.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a block diagram of a currently implemented typicaloutput stage.

FIG. 2 illustrates a graphical illustration of a power trace inarbitrary units as a function of Vcc and the output according to thetypical output stage of FIG. 1 .

FIG. 3 illustrates a block diagram of an output stage implementingvoltage amplitude tracking according to an embodiment of the disclosure.

FIG. 4 illustrates one embodiment of a logic flow for the output stageof FIG. 3 .

FIG. 5 illustrates a graphical illustration of a power trace inarbitrary units as a function of Vcc and the output according to theoutput stage of FIG. 3 .

FIG. 6 illustrates a block diagram of an output stage implementingvoltage amplitude and current density tracking according to anembodiment of the disclosure.

FIG. 7 illustrates one embodiment of a logic flow for the output stageof FIG. 6 .

FIG. 8 illustrates a graphical illustration of a power trace inarbitrary units as a function of Vcc and the output according to theoutput stage of FIG. 6 .

FIG. 9 illustrates an embodiment of a system that may be suitable forimplementing embodiments of the disclosure.

FIG. 10 illustrates embodiments of a small form factor device in whichthe system of FIG. 9 may be embodied.

DETAILED DESCRIPTION

Various embodiments are disclosed that reduce power in transceiverequipment. In particular, power reduction in equipment designed fortransmitting signals characterized by a wide dynamic range (e.g.,variation in signal amplitude). An example of such equipment may be atransmitter within a transceiver device. However, the embodimentsdescribed herein may also be applied to the receiver path within atransceiver device. For purposes of illustration, the embodimentsdescribed herein reference Multimedia Over Coax Alliance (MoCA)transceiver systems such as deployed in cable television systems orsatellite television systems. The embodiments are not limited to thiscontext and may be extended to any application having similar variabletransmission and reception power requirements.

MoCA applications typically deploy a unicast transmission with channelbandwidths ranging from 50 to 100 MHz within an overall transmissionband of approximately 950 to 1700 MHz. The transmission amplitude may bein the range 70 to 110 dBuV, or 9 mVpp to 0.9 Vpp, and the receptionamplitude may be in the range 35 to 110 dBuV, or 0.2 mVpp to 0.9 Vpp,into a characteristic impedance of 75 ohms.

Reference is now made to the drawings, wherein like reference numeralsare used to refer to like elements throughout. In the followingdescription, for purposes of explanation, numerous specific details areset forth in order to provide a thorough understanding thereof. It maybe evident, however, that the novel embodiments can be practiced withoutthese specific details. In other instances, well known structures anddevices are shown in block diagram form in order to facilitate adescription thereof. The intention is to cover all modifications,equivalents, and alternatives falling within the spirit and scope of theclaimed subject matter.

Included herein is a set of flow charts representative of exemplarymethodologies for performing novel aspects of the disclosedarchitecture. While, for purposes of simplicity of explanation, the oneor more methodologies shown herein, for example, in the form of a flowchart or flow diagram, are shown and described as a series of acts, itis to be understood and appreciated that the methodologies are notlimited by the order of acts, as some acts may, in accordance therewith,occur in a different order and/or concurrently with other acts from thatshown and described herein. For example, those skilled in the art willunderstand and appreciate that a methodology could alternatively berepresented as a series of interrelated states or events, such as in astate diagram. Moreover, not all acts illustrated in a methodology maybe required for a novel implementation.

FIG. 1 illustrates a block diagram of a currently implemented typicaloutput stage. The output stage 100 shows a transconductance stagecomprised of an amplifier (gm) gain stage 120 sourcing current into anoutput load 130, 140. In this example the output signal (Vout) 150 istaken single ended from a single load 140. In other embodiments theoutput 150 may be taken differentially from both loads 130, 140 and thenconverted to single ended by an external transformation stage (notshown). A power amplifier is implemented such that the output stage 100can support a maximum output voltage swing (single ended ordifferential). This may define a maximum supply voltage (Vcc) to preventsaturation of the transconductance stage. For example, in the singleended output, Vcc may be set at least 0.9 V above the transconductancestage output voltage to prevent saturation. In addition, there may be aDC component to the headroom corresponding to any standing current. Thelinearity of the output stage 100, which may set by the current densityand negative feedback applied within the transconductance stage, maytypically be set to deliver the required linearity at the maximumoutput.

As a consequence the power consumed by the output stage 100 (Vcc*I) isdisadvantageously constant at a maximum value set by the maximum outputamplitude, which defines a maximum Vcc and current density, irrespectiveof the output signal amplitude. This may be undesirable since power maybe wasted when the transceiver is transmitting at a reduced from peakoutput amplitude.

FIG. 2 illustrates a graphical illustration of a power trace inarbitrary units as a function of Vcc and the output signal according tothe typical output stage of FIG. 1 . In this illustration, the outputsignal can be divided into three phases: a ramp up phase, a peak phase,and a steady state phase. The output signal ramps up between 0.0 secondsand approximately 2.0 seconds. At this point the output signal jumps topeak amplitude and remains there until approximately 3.5 seconds. Theoutput signal then falls to a steady state for the rest of the time lineout to 10 seconds. It should be noted that the time values and outputsignal envelope are generally arbitrary and for illustrative purposesonly. During the entire timeline the supply voltage Vcc and powerdissipation levels remain unchanged at approximately 6.0 and 12.5respectively. Again the voltage and power values are expressed inarbitrary units for purposes of illustration. Thus, Vcc and byconsequence the power dissipation do not decrease when the output signalis at a reduced from peak amplitude.

Various embodiments are directed to apparatuses and methods to reduceaverage power dissipation in transceiver stages such as power amplifiersand low noise amplifiers (LNAs) that process varying output amplitudesby varying the supply voltage in sympathy with the amplitude of thesignal and/or the stage current density which may also be varied insympathy with the signal amplitude.

A first embodiment of an output stage as applied in a transmission poweramplifier may include a DAC that converts a digital output signal to ananalog modulated carrier which outputs to a transconductance stage. Thetransconductance stage may be preceded by a variable gain stage or maycontain a gain control facility. The output stage may be coupled to theoutput of the transconductance stage, where the output stage provides asingle ended output to a cable network, for instance, with acharacteristic impedance of 75 ohms. The output stage may include adifferential to single ended transformation. An output amplitude setstage may produce a control signal to the variable gain stage to controlthe output amplitude. In addition the output amplitude set stage mayalso control the current density of the output stage in dependence ofthe output amplitude, whereby a greater amplitude requires a greatercurrent density to provide the required linearity in the output stage.An amplitude to Vcc correlator stage may receive the output from theamplitude set stage and may generate an output proportional to eitherthe commanded output amplitude or the commanded current density or both.A buck regulator whose voltage reference input may be coupled to theoutput of the amplitude to Vcc correlator stage and whose voltage outputmay provide a supply voltage to the output stage. The buck regulator maybe implemented such that a loop bandwidth is greater than a rate ofvariation in output amplitude. The buck regulator may, in alternateembodiments, be a boost regulator. The buck (or boost) regulator may beimplemented with an analog or digital control loop.

In operation through application of the voltage regulator to generatethe output stage, the supply voltage Vcc may be arranged to vary inproportion to a commanded output amplitude. This variation maycorrespond to a linear relationship with the output amplitude (e.g.,when the output amplitude increases by ΔVpp then Vcc increases by K1*ΔV)or to a linear relationship with the current density (e.g., when thecurrent density increases by ΔI then Vcc increases by K2*ΔI*loadimpedance) or both, where K1 and K2 are constants.

A nominal DC voltage on Vcc may be set corresponding to the conditionwith no output signal. This may be a condition with no output, withminimum current density, or both. This would be the minimum possiblevoltage to avoid saturation of the output stage and would be the minimumoutput voltage provided by the Buck (or boost) regulator.

When the output stage is transmitting, an amplitude to Vcc correlatorstage may generate a control signal proportional to the outputamplitude, current density, or both. Vcc may vary in sympathy with thiscontrol signal and hence the transmitted amplitude, with constituentelements of voltage amplitude, current density, or both.

Idealized simulations comparing the typical output stage architecturewith a Vcc control based architecture on amplitude only and with a Vcccontrol based architecture on both amplitude and current density areillustrated in, FIGS. 2, 5, and 8 respectively. The graphs of FIGS. 2,5, and 8 had the same example modulation amplitude variation applied tothe implementations of FIGS. 1, 3, and 6 respectively. Empiricallycomparing the power traces for the latter two embodiments, it can beclearly seen that when transmitting at below maximum output amplitudepower is advantageously reduced.

While the embodiments described herein may be described with respect toa power amplifier stage, the embodiments could equally be deployed inany stage which processes a varying amplitude signal, such as, forexample, an LNA receiving a signal of varying amplitude.

FIG. 3 illustrates a block diagram of an output stage 300 implementingvoltage amplitude tracking according to an embodiment of the disclosure.A modulated output data generator 105 may output two digital signalsthat depend on an output signal (Vout) 150. The output signal may be fedinto a coaxial cable 155 having a characteristic impedance of 75 ohms.

A first digital signal may represent the modulation data and the seconddigital signal may represent an amplitude of the modulation data. Theamplitude of the modulation data may correspond to the average of themodulation on the output signal to prevent it from reacting to shortterm variations in amplitude.

A digital-to-analog converter (DAC) 110 may convert the digitalrepresentation of the modulation data into an analog representation ofthe modulation data. The analog representation may be the modulatedcarrier or the modulation envelope. In the modulation envelope case, theanalog output would be modulated onto a carrier (not shown).

The analog modulated carrier signal may be passed to an amplifier (gm)gain stage 120. The gain stage 120 may provide a variable gain to themodulated carrier into an output load 130, 140 to create an outputsignal Vout 150. The gain stage 120 may be a power amplifier (singleended or differential), for instance. The gain stage 120 may be poweredby a modified supply voltage VccOP. The modified supply voltage VccOPmay be provided by a buck regulator component 170.

One refinement to the output stage 300, termed voltage amplitudetracking, may reduce the average power dissipation for the entire outputstage 300. Voltage amplitude tracking varies the supply voltage for thegain stage 120 in proportion to the amplitude of the modulation data. Anamplitude to Vcc correlator component 160 converts the current amplitudeof the modulation data into a required supply voltage (VccOP) for thegain stage 120. The required supply voltage VccOP may increase inproportion to the required amplitude of the output signal 150 andmaintain an output bias on the gain stage 120 at a level appropriate toprevent clipping. Clipping may occur when the voltage on the load 130,140 becomes too low.

The buck regulator 170 may be a switched mode DC to DC converter thatmay generate the supply voltage VccOP. VccOP may be controlled by themark/space ratio of a pulse width modulated (PWM) generator (not shown).The PWM generator may be controlled by a feedback loop to set the outputto a desired value. The buck regulator 170 may operate from an inputvoltage Vccin.

FIG. 4 illustrates one embodiment of a logic flow 400 for the outputstage 300 of FIG. 3 . The logic flow 400 may be representative of someor all of the operations executed by one or more embodiments describedherein that may implement voltage amplitude tracking when managing powerin a transceiver.

In the illustrated embodiment shown in FIG. 4 , the logic flow 400 maygenerate a modulated output signal at block 410. For example, themodulated output data generator 105 may output two digital signals thatdepend on an output signal (Vout) 150. A first digital signal mayrepresent the modulation data and the second digital signal mayrepresent an amplitude of the modulation data. The amplitude of themodulation data may correspond to the average of the modulation on theoutput signal to prevent it from reacting to short term variations inamplitude. The embodiments are not limited in this context.

The logic flow 400 may determine an amplitude for the modulated outputsignal at block 420. For example, the amplitude to Vcc correlatorcomponent 160 may generate a control signal proportional to the outputsignal amplitude. The embodiments are not limited in this context.

The logic flow 400 may adjust or modify a supply voltage based on theamplitude of the modulated output signal 150 at block 430. For example,the buck regulator component 170 may convert the amplitude of themodulation data into a required supply voltage (VccOP) for the gainstage 120. The required supply voltage VccOP may be modified to increaseor decrease in proportion to the required amplitude of the output signal150 and maintain an output bias on the gain stage 120 at a levelappropriate to prevent clipping. Clipping may occur when the voltage onthe load 130, 140 becomes too low. The embodiments are not limited inthis context.

The logic flow 400 may apply the adjusted or modified supply voltageVccOP to the gain stage 120 for the modulated output signal 150 at block440. For example, the buck regulator component 170 may have a voltagereference input coupled to the output of the amplitude to Vcc correlatorcomponent 160 and may provide a supply voltage VccOP to the outputstage. The buck regulator component 170 may be implemented such that aloop bandwidth is greater than a rate of variation in output amplitude.The buck regulator component 170 may, in alternate embodiments, be aboost regulator. The buck (or boost) regulator component 170 may beimplemented with an analog or digital control loop. The embodiments arenot limited in this context.

FIG. 5 illustrates a graphical illustration of a power trace inarbitrary units as a function of the supply voltage (VccOP) and theoutput signal according to the output stage of FIG. 3 . FIG. 5graphically represents the voltage amplitude tracking embodiment. Inthis illustration, the output signal can be divided into three phases: aramp up phase, a peak phase, and a steady state phase. The output signalramps up between 0.0 seconds and approximately 2.0 seconds. At thispoint the output signal jumps to peak amplitude and remains there untilapproximately 4.0 seconds. The output signal then falls to a steadystate for the rest of the time line out to 10 seconds. It should benoted that the time, voltage, power values, and output signal envelopeare expressed in arbitrary units for purposes of illustration.

During the ramp up phase, VccOP and the power dissipation levels trackthe peak amplitude of the output signal such that VccOP is approximately4.0 when the output signal is at 2.0 at time 0.0 and rises (somewhatlinearly) to approximately 4.6 when the output amplitude rises toapproximately 3.7. Similarly, power dissipation linearly rises inproportion to the output signal amplitude during the ramp up phase.During the peak phase, VccOP jumps to and holds at a value ofapproximately 6.1 while power dissipation also jumps to and holds at avalue of 12.5. During the steady state phase, the output signal may beoperating at below peak levels. VccOP drops to and holds at a value ofapproximately 4.0 while power dissipation also drops to and holds at avalue of approximately 7.5. Thus, VccOP and the power dissipation varylinearly when the output signal is at a “reduced from peak” amplitude.This results in reduced power dissipation when the output signal is notat peak amplitude because the supply voltage is tied to the currentamplitude of the output signal rather than being set to always operateat the highest peak amplitude of the output signal.

FIG. 6 illustrates a block diagram of an output stage 600 implementingvoltage amplitude and current density tracking according to anembodiment of the disclosure. A modulated output data generator 105 mayoutput two digital signals that depend on an output signal (Vout) 150.The output signal may be fed into a coaxial cable 155 having acharacteristic impedance of 75 ohms.

A first digital signal may represent the modulation data and the seconddigital signal may represent an amplitude of the modulation data. Theamplitude of the modulation data may correspond to the average of themodulation on the output signal to prevent it from reacting to shortterm variations in amplitude.

A digital-to-analog converter (DAC) 110 may convert the digitalrepresentation of the modulation data into an analog representation ofthe modulation data. The analog representation may be the modulatedcarrier or the modulation. In the modulation case, the analog outputwould be modulated onto a carrier (not shown).

The analog modulated carrier signal may be passed to an amplifier (gm)gain stage 120. The gain stage 120 may provide a variable gain to themodulated carrier into an output load 130, 140 to create an outputsignal Vout 150. The gain stage 120 may be a power amplifier, forinstance. The gain stage 120 may be powered by a modified supply voltageVccOP. The modified supply voltage VccOP may be provided by a buckregulator component 170.

One refinement to the output stage 600, termed voltage amplitudetracking, may reduce the average power dissipation for the entire outputstage 600. Voltage amplitude tracking varies the supply voltage for thegain stage 120 in proportion to the amplitude of the modulation data. Anamplitude to Vcc correlator component 160 converts the current amplitudeof the modulation data into a required supply voltage (VccOP) for thegain stage 120. The required supply voltage VccOP may increase inproportion to the required amplitude of the output signal 150 andmaintain an output bias on the gain stage 120 at a level appropriate toprevent clipping. Clipping may occur when the voltage on the load 130,140 becomes too low.

The buck regulator 170 may be a switched mode DC to DC converter thatmay generate the variable modified supply voltage VccOP. VccOP may becontrolled by the mark/space ratio of a pulse width modulated (PWM)generator (not shown). The PWM generator may be controlled by a feedbackloop to set the output to a desired value. The buck regulator 170 mayoperate from an input voltage Vccin.

A further refinement to the output stage 600, termed current densitytracking, may further reduce power dissipation for the overall outputstage 600. An amplitude to bias correlator component 180 may convert thecurrent amplitude of the modulation data into a bias current 190 for thegain stage 120. The bias current 190 may increase in proportion to therequired output signal 150 amplitude and maintain an output bias on thegain stage 120 at a level appropriate to prevent clipping.

In another embodiment, the input to the amplitude to bias correlatorcomponent 180 may come from the amplitude to Vcc correlator 160 or fromVccOP. This is because VccOP and the bias current 190 may both bedependent on the output signal amplitude.

The bias current 190, in combination with the modified supply voltageVccOP, may provide sufficient current to achieve the required linearityfor the output signal Vout 150. For instance, larger signals may requirea larger bias current 190 to minimize distortion. Conversely, smallersignals may require a smaller bias current 190.

FIG. 7 illustrates one embodiment of a logic flow 700 for the outputstage 600 of FIG. 6 . The logic flow 700 may be representative of someor all of the operations executed by one or more embodiments describedherein that may implement voltage amplitude and current density trackingwhen managing power in a transceiver.

In the illustrated embodiment shown in FIG. 7 , the logic flow 700 maygenerate a modulated output signal at block 710. For example, themodulated output data generator 105 may output two digital signals thatdepend on an output signal (Vout) 150. A first digital signal mayrepresent the modulation data and the second digital signal mayrepresent an amplitude of the modulation data. The amplitude of themodulation data may correspond to the average of the modulation on theoutput signal to prevent it from reacting to short term variations inamplitude. The embodiments are not limited in this context.

The logic flow 700 may determine an amplitude for the modulated outputsignal at block 720. For example, the amplitude to Vcc correlatorcomponent 160 may generate a control signal proportional to the outputsignal amplitude. The embodiments are not limited in this context.

The logic flow 700 may adjust or modify a supply voltage based on theamplitude of the modulated output signal 150 at block 730. For example,the buck regulator component 170 may convert the amplitude of themodulation data into a required supply voltage (VccOP) for the gainstage 120. The required supply voltage VccOP may be modified to increaseor decrease in proportion to the required amplitude of the output signal150 and maintain an output bias on the gain stage 120 at a levelappropriate to prevent clipping. Clipping may occur when the voltage onthe load 130, 140 becomes too low. The embodiments are not limited inthis context.

The logic flow 700 may determine a bias current 190 for the gain stage120 for the modulated output signal at block 740. For example, theamplitude to bias correlator component 180 may convert the amplitude ofthe modulation data into a bias current 190 for the gain stage 120. Thebias current 190 may increase in proportion to the required outputsignal 150 amplitude and maintain an output bias on the gain stage 120at a level appropriate to prevent clipping. The embodiments are notlimited in this context.

The logic flow 700 may apply the bias current 190 to the gain stage 120for the modulated output signal at block 750. For example, the biascurrent 190, in combination with the modified supply voltage VccOP, mayprovide sufficient current to the gain stage 120 to achieve the requiredlinearity for the output signal Vout 150. For instance, larger signalsmay require a larger bias current 190 to minimize distortion.Conversely, smaller signals may require a smaller bias current 190. Theembodiments are not limited in this context.

The logic flow 700 may apply the adjusted or modified supply voltageVccOP to the gain stage 120 for the modulated output signal 150 at block740. For example, the buck regulator component 170 may have a voltagereference input coupled to the output of the amplitude to Vcc correlatorcomponent 160 and may provide a supply voltage VccOP to the outputstage. The buck regulator component 170 may be implemented such that aloop bandwidth is greater than a rate of variation in output amplitude.The buck regulator component 170 may, in alternate embodiments, be aboost regulator. The buck (or boost) regulator component 170 may beimplemented with an analog or digital control loop. The embodiments arenot limited in this context.

FIG. 8 illustrates a graphical illustration of a power trace inarbitrary units as a function of Vcc and the output according to theoutput stage of FIG. 6 . FIG. 8 graphically represents the voltageamplitude and current density tracking embodiment. In this illustration,the output signal can be divided into three phases: a ramp up phase, apeak phase, and a steady state phase. The output signal ramps up between0.0 seconds and approximately 2.0 seconds. At this point the outputsignal jumps to peak amplitude and remains there until approximately 4.0seconds. The output signal then falls to a steady state for the rest ofthe time line out to 10 seconds. It should be noted that the time,voltage, power values, and output signal envelope are expressed inarbitrary units for purposes of illustration.

During the ramp up phase, VccOP and the power dissipation levels trackthe amplitude of the output signal such that VccOP is approximately 4.0when the output signal is at 2.0 at time 0.0 and rises (somewhatlinearly) to approximately 4.6 when the output amplitude rises toapproximately 3.7. Similarly, power dissipation starts lower andlinearly rises in proportion to the output signal amplitude during theramp up phase. During the peak phase, VccOP jumps to and holds at avalue of approximately 6.1 while power dissipation also jumps to andholds at a value of approximately 12.5. During the steady state phase,the output signal may be operating at below peak levels. VccOP drops toand holds at a value of approximately 2.8 while power dissipation alsodrops to and holds at a value of approximately 2.5. Thus, VccOP and thepower dissipation vary linearly when the output signal is at a “reducedfrom peak” amplitude. Combining voltage amplitude and current densitytracking results in even greater reduced power dissipation when theoutput signal is not at peak amplitude.

Various embodiments may be implemented using hardware elements, softwareelements, or a combination of both. Examples of hardware elements mayinclude processors, microprocessors, circuits, circuit elements (e.g.,transistors, resistors, capacitors, inductors, and so forth), integratedcircuits, application specific integrated circuits (ASIC), programmablelogic devices (PLD), digital signal processors (DSP), field programmablegate array (FPGA), logic gates, registers, semiconductor device, chips,microchips, chip sets, and so forth. Examples of software may includesoftware components, programs, applications, computer programs,application programs, system programs, machine programs, operatingsystem software, middleware, firmware, software modules, routines,subroutines, functions, methods, procedures, software interfaces,application program interfaces (API), instruction sets, computing code,computer code, code segments, computer code segments, words, values,symbols, or any combination thereof. Determining whether an embodimentis implemented using hardware elements and/or software elements may varyin accordance with any number of factors, such as desired computationalrate, power levels, heat tolerances, processing cycle budget, input datarates, output data rates, memory resources, data bus speeds and otherdesign or performance constraints.

FIG. 9 illustrates an embodiment of a system 900 that may be suitablefor implementing the power management embodiments of the disclosure. Inembodiments, system 900 may be a system capable of implementing thepower management embodiments described above although system 900 is notlimited to this context. For example, system 900 may be incorporatedinto a personal computer (PC), laptop computer, ultra-laptop computer,tablet, touch pad, portable computer, handheld computer, palmtopcomputer, personal digital assistant (PDA), cellular telephone,combination cellular telephone/PDA, television, smart device (e.g.,smart phone, smart tablet or smart television), mobile internet device(MID), messaging device, data communication device, and so forth.

In embodiments, system 900 comprises a platform 902 coupled to a display920. Platform 902 may receive content from a content device such ascontent services device(s) 930 or content delivery device(s) 940 orother similar content sources. A navigation controller 950 comprisingone or more navigation features may be used to interact with, forexample, platform 902 and/or display 920. Each of these components isdescribed in more detail below.

In embodiments, platform 902 may comprise any combination of a chipset905, processor(s) 910, memory 912, storage 914, graphics subsystem 915,applications 916 and/or radio 918. Chipset 905 may provideintercommunication among processor 910, memory 912, storage 914,graphics subsystem 915, applications 916 and/or radio 918. For example,chipset 905 may include a storage adapter (not depicted) capable ofproviding intercommunication with storage 914.

Processor(s) 910 may be implemented as Complex Instruction Set Computer(CISC) or Reduced Instruction Set Computer (RISC) processors, x86instruction set compatible processors, multi-core, or any othermicroprocessor or central processing unit (CPU). In embodiments,processor(s) 910 may comprise dual-core processor(s), dual-core mobileprocessor(s), and so forth.

Memory 912 may be implemented as a volatile memory device such as, butnot limited to, a Random Access Memory (RAM), Dynamic Random AccessMemory (DRAM), or Static RAM (SRAM).

Storage 914 may be implemented as a non-volatile storage device such as,but not limited to, a magnetic disk drive, optical disk drive, tapedrive, an internal storage device, an attached storage device, flashmemory, battery backed-up SDRAM (synchronous DRAM), and/or a networkaccessible storage device. In embodiments, storage 914 may comprisetechnology to increase the storage performance enhanced protection forvaluable digital media when multiple hard drives are included, forexample.

Graphics subsystem 915 may perform processing of images such as still orvideo for display. Graphics subsystem 915 may be a graphics processingunit (GPU) or a visual processing unit (VPU), for example. An analog ordigital interface may be used to communicatively couple graphicssubsystem 915 and display 920. For example, the interface may be any ofa High-Definition Multimedia Interface, DisplayPort, wireless HDMI,and/or wireless HD compliant techniques. Graphics subsystem 915 could beintegrated into processor 910 or chipset 905. Graphics subsystem 915could be a stand-alone card communicatively coupled to chipset 905.

The graphics and/or video processing techniques described herein may beimplemented in various hardware architectures. For example, graphicsand/or video functionality may be integrated within a chipset.Alternatively, a discrete graphics and/or video processor may be used.As still another embodiment, the graphics and/or video functions may beimplemented by a general purpose processor, including a multi-coreprocessor. In a further embodiment, the functions may be implemented ina consumer electronics device.

Radio 918 may include one or more radios capable of transmitting andreceiving signals using various suitable wireless communicationstechniques. Such techniques may involve communications across one ormore wireless networks. Exemplary wireless networks include (but are notlimited to) wireless local area networks (WLANs), wireless personal areanetworks (WPANs), wireless metropolitan area network (WMANs), cellularnetworks, and satellite networks. In communicating across such networks,radio 918 may operate in accordance with one or more applicablestandards in any version.

In embodiments, display 920 may comprise any television type monitor ordisplay. Display 920 may comprise, for example, a computer displayscreen, touch screen display, video monitor, television-like device,and/or a television. Display 920 may be digital and/or analog. Inembodiments, display 920 may be a holographic display. Also, display 920may be a transparent surface that may receive a visual projection. Suchprojections may convey various forms of information, images, and/orobjects. For example, such projections may be a visual overlay for amobile augmented reality (MAR) application. Under the control of one ormore software applications 916, platform 902 may display user interface922 on display 920.

In embodiments, content services device(s) 930 may be hosted by anynational, international and/or independent service and thus accessibleto platform 902 via the Internet, for example. Content servicesdevice(s) 930 may be coupled to platform 902 and/or to display 920.Platform 902 and/or content services device(s) 930 may be coupled to anetwork 960 to communicate (e.g., send and/or receive) media informationto and from network 960. Content delivery device(s) 940 also may becoupled to platform 902 and/or to display 920.

In embodiments, content services device(s) 930 may comprise a cabletelevision box, personal computer, network, telephone, Internet enableddevices or appliance capable of delivering digital information and/orcontent, and any other similar device capable of unidirectionally orbidirectionally communicating content between content providers andplatform 902 and/display 920, via network 960 or directly. It will beappreciated that the content may be communicated unidirectionally and/orbidirectionally to and from any one of the components in system 900 anda content provider via network 960. Examples of content may include anymedia information including, for example, video, music, medical andgaming information, and so forth.

Content services device(s) 930 receives content such as cable televisionprogramming including media information, digital information, and/orother content. Examples of content providers may include any cable orsatellite television or radio or Internet content providers. Theprovided examples are not meant to limit embodiments of the invention.

In embodiments, platform 902 may receive control signals from navigationcontroller 950 having one or more navigation features. The navigationfeatures of controller 950 may be used to interact with user interface922, for example. In embodiments, navigation controller 950 may be apointing device that may be a computer hardware component (specificallyhuman interface device) that allows a user to input spatial (e.g.,continuous and multi-dimensional) data into a computer. Many systemssuch as graphical user interfaces (GUI), and televisions and monitorsallow the user to control and provide data to the computer or televisionusing physical gestures.

Movements of the navigation features of controller 950 may be echoed ona display (e.g., display 920) by movements of a pointer, cursor, focusring, or other visual indicators displayed on the display. For example,under the control of software applications 916, the navigation featureslocated on navigation controller 950 may be mapped to virtual navigationfeatures displayed on user interface 922, for example. In embodiments,controller 950 may not be a separate component but integrated intoplatform 902 and/or display 920. Embodiments, however, are not limitedto the elements or in the context shown or described herein.

In embodiments, drivers (not shown) may comprise technology to enableusers to instantly turn on and off platform 902 like a television withthe touch of a button after initial boot-up, when enabled, for example.Program logic may allow platform 902 to stream content to media adaptorsor other content services device(s) 930 or content delivery device(s)940 when the platform is turned “off” In addition, chip set 905 maycomprise hardware and/or software support for 5.1 surround sound audioand/or high definition 9.1 surround sound audio, for example. Driversmay include a graphics driver for integrated graphics platforms. Inembodiments, the graphics driver may comprise a peripheral componentinterconnect (PCI) Express graphics card.

In various embodiments, any one or more of the components shown insystem 900 may be integrated. For example, platform 902 and contentservices device(s) 930 may be integrated, or platform 902 and contentdelivery device(s) 940 may be integrated, or platform 902, contentservices device(s) 930, and content delivery device(s) 940 may beintegrated, for example. In various embodiments, platform 902 anddisplay 920 may be an integrated unit. Display 920 and content servicedevice(s) 930 may be integrated, or display 920 and content deliverydevice(s) 940 may be integrated, for example. These examples are notmeant to limit the invention.

In various embodiments, system 900 may be implemented as a wirelesssystem, a wired system, or a combination of both. When implemented as awireless system, system 900 may include components and interfacessuitable for communicating over a wireless shared media, such as one ormore antennas, transmitters, receivers, transceivers, amplifiers,filters, control logic, and so forth. An example of wireless sharedmedia may include portions of a wireless spectrum, such as the RFspectrum and so forth. When implemented as a wired system, system 900may include components and interfaces suitable for communicating overwired communications media, such as input/output (I/O) adapters,physical connectors to connect the I/O adapter with a correspondingwired communications medium, a network interface card (NIC), disccontroller, video controller, audio controller, and so forth. Examplesof wired communications media may include a wire, cable, metal leads,printed circuit board (PCB), backplane, switch fabric, semiconductormaterial, twisted-pair wire, co-axial cable, fiber optics, and so forth.

Platform 902 may establish one or more logical or physical channels tocommunicate information. The information may include media informationand control information. Media information may refer to any datarepresenting content meant for a user. Examples of content may include,for example, data from a voice conversation, videoconference, streamingvideo, electronic mail (“email”) message, voice mail message,alphanumeric symbols, graphics, image, video, text and so forth. Datafrom a voice conversation may be, for example, speech information,silence periods, background noise, comfort noise, tones and so forth.Control information may refer to any data representing commands,instructions or control words meant for an automated system. Forexample, control information may be used to route media informationthrough a system, or instruct a node to process the media information ina predetermined manner. The embodiments, however, are not limited to theelements or in the context shown or described in FIG. 9 .

As described above, system 900 may be embodied in varying physicalstyles or form factors. FIG. 10 illustrates embodiments of a small formfactor device 1000 in which system 900 may be embodied. In embodiments,for example, device 1000 may be implemented as a mobile computing devicehaving wireless capabilities. A mobile computing device may refer to anydevice having a processing system and a mobile power source or supply,such as one or more batteries, for example.

As described above, examples of a mobile computing device may include apersonal computer (PC), laptop computer, ultra-laptop computer, tablet,touch pad, portable computer, handheld computer, palmtop computer,personal digital assistant (PDA), cellular telephone, combinationcellular telephone/PDA, television, smart device (e.g., smart phone,smart tablet or smart television), mobile internet device (MID),messaging device, data communication device, and so forth.

Examples of a mobile computing device also may include computers thatare arranged to be worn by a person, such as a wrist computer, fingercomputer, ring computer, eyeglass computer, belt-clip computer, arm-bandcomputer, shoe computers, clothing computers, and other wearablecomputers. In embodiments, for example, a mobile computing device may beimplemented as a smart phone capable of executing computer applications,as well as voice communications and/or data communications. Althoughsome embodiments may be described with a mobile computing deviceimplemented as a smart phone by way of example, it may be appreciatedthat other embodiments may be implemented using other wireless mobilecomputing devices as well. The embodiments are not limited in thiscontext.

As shown in FIG. 10 , device 1000 may comprise a housing 1002, a display1004, an input/output (I/O) device 1006, and an antenna 1008. Device1000 also may comprise navigation features 1012. Display 1004 maycomprise any suitable display unit for displaying informationappropriate for a mobile computing device. I/O device 1006 may compriseany suitable I/O device for entering information into a mobile computingdevice. Examples for I/O device 1006 may include an alphanumerickeyboard, a numeric keypad, a touch pad, input keys, buttons, switches,rocker switches, microphones, speakers, voice recognition device andsoftware, and so forth. Information also may be entered into device 1000by way of microphone. Such information may be digitized by a voicerecognition device. The embodiments are not limited in this context.

Various embodiments may be implemented using hardware elements, softwareelements, or a combination of both. Examples of hardware elements mayinclude processors, microprocessors, circuits, circuit elements (e.g.,transistors, resistors, capacitors, inductors, and so forth), integratedcircuits, application specific integrated circuits (ASIC), programmablelogic devices (PLD), digital signal processors (DSP), field programmablegate array (FPGA), logic gates, registers, semiconductor device, chips,microchips, chip sets, and so forth. Examples of software may includesoftware components, programs, applications, computer programs,application programs, system programs, machine programs, operatingsystem software, middleware, firmware, software modules, routines,subroutines, functions, methods, procedures, software interfaces,application program interfaces (API), instruction sets, computing code,computer code, code segments, computer code segments, words, values,symbols, or any combination thereof. Determining whether an embodimentis implemented using hardware elements and/or software elements may varyin accordance with any number of factors, such as desired computationalrate, power levels, heat tolerances, processing cycle budget, input datarates, output data rates, memory resources, data bus speeds and otherdesign or performance constraints.

One or more aspects of at least one embodiment may be implemented byrepresentative instructions stored on a machine-readable medium whichrepresents various logic within the processor, which when read by amachine causes the machine to fabricate logic to perform the techniquesdescribed herein. Such representations, known as “IP cores” may bestored on a tangible, machine readable medium and supplied to variouscustomers or manufacturing facilities to load into the fabricationmachines that actually make the logic or processor.

One or more aspects of at least one embodiment may be implemented byrepresentative instructions stored on a machine-readable medium whichrepresents various logic within the processor, which when read by amachine causes the machine to fabricate logic to perform the techniquesdescribed herein. Such representations, known as “IP cores” may bestored on a tangible, machine readable medium and supplied to variouscustomers or manufacturing facilities to load into the fabricationmachines that actually make the logic or processor.

Some embodiments may be described using the expression “one embodiment”or “an embodiment” along with their derivatives. These terms mean that aparticular feature, structure, or characteristic described in connectionwith the embodiment is included in at least one embodiment. Theappearances of the phrase “in one embodiment” in various places in thespecification are not necessarily all referring to the same embodiment.Further, some embodiments may be described using the expression“coupled” and “connected” along with their derivatives. These terms arenot necessarily intended as synonyms for each other. For example, someembodiments may be described using the terms “connected” and/or“coupled” to indicate that two or more elements are in direct physicalor electrical contact with each other. The term “coupled,” however, mayalso mean that two or more elements are not in direct contact with eachother, but yet still co-operate or interact with each other.

It is emphasized that the Abstract of the Disclosure is provided toallow a reader to quickly ascertain the nature of the technicaldisclosure. It is submitted with the understanding that it will not beused to interpret or limit the scope or meaning of the claims. Inaddition, in the foregoing Detailed Description, it can be seen thatvarious features are grouped together in a single embodiment for thepurpose of streamlining the disclosure. This method of disclosure is notto be interpreted as reflecting an intention that the claimedembodiments require more features than are expressly recited in eachclaim. Rather, as the following claims reflect, inventive subject matterlies in less than all features of a single disclosed embodiment. Thusthe following claims are hereby incorporated into the DetailedDescription, with each claim standing on its own as a separateembodiment. In the appended claims, the terms “including” and “in which”are used as the plain-English equivalents of the respective terms“comprising” and “wherein,” respectively. Moreover, the terms “first,”“second,” “third,” and so forth, are used merely as labels, and are notintended to impose numerical requirements on their objects.

What has been described above includes examples of the disclosedarchitecture. It is, of course, not possible to describe everyconceivable combination of components and/or methodologies, but one ofordinary skill in the art may recognize that many further combinationsand permutations are possible. Accordingly, the novel architecture isintended to embrace all such alterations, modifications and variationsthat fall within the spirit and scope of the appended claims.

What is claimed is:
 1. An apparatus, comprising: circuitry to provide apower supply voltage for a power amplifier based on an amplitude for amodulated carrier signal and a feedback loop for a first circuit, thecircuitry comprising: the first circuit to determine the amplitude forthe modulated carrier signal to be amplified by the power amplifier andto generate a pulse-width modulated signal based on the amplitude forthe modulated carrier signal and the feedback loop; and a second circuitto output an amplitude varying bias signal based on the pulse-widthmodulated signal, to provide a bias signal to the power amplifier tocause the provided power supply voltage to vary based on the amplitudeof the modulated carrier signal.
 2. The apparatus of claim 1, furthercomprising a digital-to-analog converter to couple with the poweramplifier to provide a bias current.
 3. The apparatus of claim 1,wherein the bias signal comprises an amplitude varying signal based onthe amplitude of the modulated carrier signal.
 4. The apparatus of claim1, further comprising a transconductance amplifier as the poweramplifier.
 5. The apparatus of claim 4, wherein the amplitude varyingbias signal is a bias voltage for the power amplifier.
 6. The apparatusof claim 5, the power amplifier comprised in a radio frequency (RF)transceiver.
 7. The apparatus of claim 1, further comprising a modulateddata generator to output a first digital signal representing modulationdata and a second digital signal representing an amplitude of themodulation data.
 8. The apparatus of claim 1, wherein the feedback loopcomprises a digital feedback signal.
 9. The apparatus of claim 1,wherein the feedback loop comprises an analog feedback signal.
 10. Amethod, comprising: determining an amplitude for a modulated carriersignal to be amplified by a power amplifier; generating, by apulse-width modulated generator circuit, a pulse-width modulated signalbased on the amplitude for the modulated carrier signal and a feedbackloop for the pulse-width modulated generator circuit; and outputting anamplitude varying bias signal based on the pulse-width modulated signal,to provide a bias signal to the power amplifier to cause a power supplyvoltage to vary based on the amplitude of the modulated carrier signal.11. The method of claim 10, wherein the feedback loop comprises adigital feedback signal.
 12. The method of claim 10, wherein thefeedback loop comprises an analog feedback signal.
 13. The method ofclaim 10, wherein the amplitude varying bias signal is a bias voltagefor the power amplifier.
 14. An apparatus, comprising: a poweramplifier; tracking circuitry to provide a power supply voltage for thepower amplifier based on an amplitude for a modulated carrier signal anda feedback loop for a first circuit, the circuitry comprising: the firstcircuit to determine the amplitude for the modulated carrier signal tobe amplified by the power amplifier and to generate a pulse-widthmodulated signal based on the amplitude for the modulated carrier signaland the feedback loop; and a second circuit to output an amplitudevarying bias signal based on the pulse-width modulated signal, toprovide a bias signal to the power amplifier to cause the provided powersupply voltage to vary based on the amplitude of the modulated carriersignal; and bias circuitry coupled with the power amplifier to provide asecond bias signal to the power amplifier.
 15. The apparatus of claim14, wherein the amplitude varying bias signal is a bias voltage for thepower amplifier.
 16. The apparatus of claim 14, wherein the feedbackloop comprises a digital feedback signal.
 17. The apparatus of claim 14,wherein the feedback loop comprises an analog feedback signal.